Some assignments are bigger than can be done in one class period. And class time is for lecture; there isn't a lot of time for students to work problems on their own.
So we're just dealing with what (some) students have always done: get someone else to write the report or do the math homework. Or have parents pay a tutor to help. Or use Cliff's Notes instead of reading the book. But now it's trivially easy and free. There are no obstacles to cheating other than knowing it's wrong and self-defeating, and those are things that young people don't really have a well-developed sense about.
So we're just dealing with what (some) students have always done: get someone else to write the report or do the math homework. Or have parents pay a tutor to help. Or use Cliff's Notes instead of reading the book. But now it's trivially easy and free. There are no obstacles to cheating other than knowing it's wrong and self-defeating, and those are things that young people don't really have a well-developed sense about.